I guess I have a similar problem with winter lagering. I use a side-by-side refrigerator that is in my uninsulated shop, during warm months, i.e., above 50F. Right now temps here in southern Oregon are fluctuating between highs in the mid-upper 40s; lows in the low 30s. I have the older, gray Johnson controller/thermostat that controls the refrigerator, so, providing adequate heat is my issue. Should I hang a low watt light bulb in the refridgerator, and just leave it on with the Johnson? How low can I go with the bulb wattage? I wonder what type of strain this will put on the refrigerator's compressor?